Field of the Invention
The present invention relates to a liquid crystal display element which is useful as an electro-optical liquid crystal display material.
Description of Related Art
An active matrix type liquid crystal display device has excellent display quality, and thus has been used in mobile terminals, liquid crystal television sets, projectors, computers, or the like, and has penetrated the market. For the active matrix display mode used in display devices, TFT (Thin Film Transistor), MIM (Metal Insulator Metal), and the like are used, and in this mode, it is important that they have a high voltage maintenance ratio. Further, in order to obtain wider visual characteristics, a TFT display formed by a combination with VA (Vertical Alignment) mode, an IPS (In-Plane-Switching) mode, an OCB (Optically Compensated Bend) mode, and the like has been proposed, or in order to obtain lighter display, a reflective type of an ECB (Electrically Controlled Birefringence) mode has been proposed. In response to such a display element, new liquid crystal compound or liquid crystal compositions are still currently being proposed.
It has been known that an increase in K33 (bend elastic constant) can improve the response speed with respect to the electric field of a liquid crystal molecule in any of various modes of TN (Twisted Nematic), STN (Super Twisted Nematic), VA, and the like.
For example, in Published Japanese Translation No. 2007-529767 of the PCT International Publication, a composition having a relatively higher K3 (bend elastic constant) of 36.7 pN has been disclosed.